New method IssueAddCommand::get_tag_id()

The new method throws ClientException if the given Tag element is
invalid, thus preventing issue creation via REST API in this case.

Previously the issue would be created even though the API call was
failing with a 404 error caused by the invalid tag.

Fixes #26076

core/commands/IssueAddCommand.php

@@ -218,13 +218,15 @@ protected function validate() {
 			}
 		}
 
-		if( isset( $t_issue['tags'] ) && is_array( $t_issue['tags'] ) && !tag_can_create( $this->user_id ) ) {
+		# Validate tags and make sure user is allowed to create them if needed
+		if( isset( $t_issue['tags'] ) && is_array( $t_issue['tags'] ) ) {
 			foreach( $t_issue['tags'] as $t_tag ) {
-				if( isset( $t_tag['id'] ) && $t_tag['id'] === -1 ) {
+				$t_tag_id = $this->get_tag_id( $t_tag );
+				if( $t_tag_id === -1  && !tag_can_create( $this->user_id ) ) {
 					throw new ClientException(
 						sprintf( "User '%d' can't create tag '%s'.", $this->user_id, $t_tag['name'] ),
 						ERROR_TAG_NOT_FOUND );
-					}
+				}
 			}
 		}
 
@@ -346,7 +348,7 @@ protected function process() {
 		if( isset( $t_issue['tags'] ) && is_array( $t_issue['tags'] ) ) {
 			$t_tags = array();
 			foreach( $t_issue['tags'] as $t_tag ) {
-				if( isset( $t_tag['id'] ) && $t_tag['id'] === -1 ) {
+				if( $this->get_tag_id( $t_tag ) === -1 ) {
 					$t_tag['id'] = tag_create( $t_tag['name'], $this->user_id );
 					log_event( LOG_WEBSERVICE,
 						"created new tag '" . $t_tag['name'] . "' id '" . $t_tag['id'] . "'"
@@ -458,5 +460,45 @@ protected function process() {
 
 		return array( 'issue_id' => $t_issue_id );
 	}
+
+	/**
+	 * Retrieves the Tag ID for the given Tag element.
+	 *
+	 * A tag element is an array with either an 'id', a 'name' key, or both.
+	 * If id is provided, check that it exists and return it;
+	 * if name is supplied, look it up and return the corresponding ID, or
+	 * -1 if not found (meaning Tag should be created).
+	 *
+	 * @param array $p_tag Tag element
+	 * @return integer Tag ID or -1 if tag must be created
+	 * @throws ClientException
+	 */
+	private function get_tag_id( array $p_tag ) {
+		if( isset( $p_tag['id'] ) && $p_tag['id'] != -1 ) {
+			$t_tag_id = $p_tag['id'];
+			if( !tag_exists( $t_tag_id ) ) {
+				throw new ClientException(
+					"Tag with id $t_tag_id not found.",
+					ERROR_TAG_NOT_FOUND
+				);
+			}
+		} elseif( isset( $p_tag['name'] ) ) {
+			$t_existing_tag = tag_get_by_name( $p_tag['name'] );
+			if( $t_existing_tag === false && isset( $p_tag['id'] ) && $p_tag['id'] != -1 ) {
+				throw new ClientException(
+					"Tag {$p_tag['name']} not found.",
+					ERROR_TAG_NOT_FOUND
+				);
+			}
+
+			$t_tag_id = $t_existing_tag['id'];
+		} else {
+			throw new ClientException(
+				'Tag without id or name.',
+				ERROR_TAG_NAME_INVALID
+			);
+		}
+		return $t_tag_id;
+	}
 }